Expand tests for unicode property escapes

test/fixtures/test_grammars/unicode_classes/corpus.txt

@@ -1,9 +1,32 @@
-============================
-Letters
-======================
+===============
+Uppercase words
+===============
 
-Aბㄱ
+Δბㄱ  Ψ  Ɓƀ  Ƒ  Ɣ  Śřř
 
 ---
 
-(expression (upper))
+(program
+  (upper) (upper) (upper) (upper) (upper) (upper))
+
+================
+Lowercase words
+================
+
+śś  ťť  ßß
+
+---
+
+(program
+  (lower) (lower) (lower))
+
+================
+Math symbols
+================
+
+≺ ≼ ≠ ≝ ⨔∑
+
+---
+
+(program
+  (math_sym) (math_sym) (math_sym) (math_sym) (math_sym))

test/fixtures/test_grammars/unicode_classes/grammar.json

@@ -6,13 +6,16 @@
   ],
 
   "rules": {
-    "expression": {
-      "type": "CHOICE",
-      "members": [
-        {"type": "SYMBOL", "name": "lower"},
-        {"type": "SYMBOL", "name": "upper"},
-        {"type": "SYMBOL", "name": "math_sym"}
-      ]
+    "program":  {
+      "type": "REPEAT",
+      "content": {
+        "type": "CHOICE",
+        "members": [
+          {"type": "SYMBOL", "name": "lower"},
+          {"type": "SYMBOL", "name": "upper"},
+          {"type": "SYMBOL", "name": "math_sym"}
+        ]
+      }
     },
 
     "lower": {